Interpretation ID: nht95-1.2

TYPE: INTERPRETATION-NHTSA

DATE: January 2, 1995

FROM: Jim Cawse -- Principal Scientist; George Diehl -- Standards Engineer, General Electric

TO: Philip Recht -- Chief Counsel - NHTSA

TITLE: NONE

ATTACHMT: Attached to 2/6/95 letter from Philip R. Recht to Jim Cawse and Fred (George) Diehl (A43; Std. 108)

TEXT: Dear Mr. Recht:

As GE Plastics continues to develop and introduce new products for the Automotive Lighting marketplace, it is extremely important that we continue to adhere to the SAE testing protocol as delineated in SAE J576C, to ensure that our products meet the pass /fail three year natural weathering criteria in South Florida and Arizona. The Design of Experiment (DOE) approach we discussed with you in August and September, 1994, will enable us to generate a much wider spread of data utilizing dependent and indepe ndent variables including haze. Yellowness Index (YI), color shift, thicknesses, formulations, colors, color concentrations, and coatings. This will supply very meaningful results for us and our customers in that we will be able to extract more results from less testing.

As a result of our discussions with NHTSA, AAMVA (now AMECA), and the major automotive and automotive lighting players, we have modified our initial approach to incorporate the important concerns of all parties. These include:

* The thicknesses used in the study will be at least the three minimum as called out by SAE J576C (0.062, 0.125, and 0.250 inches). We have added the 0.040" thickness as well.

* The formulations (base material recipes) used in the study will be commercial formulations and the results of the study will be usable for only those formulations (i.e., no blends of two formulations).

* Each coating will be tested at least once on each formulation.

* Each color candidate will be tested in a low and high color concentration so that interpolations can be made from the test results for color concentrations that fall in between.

* The final list of coatings is being firmed up as of this writing, and actually is being expanded beyond the list presented in previous meetings.

We would appreciate your written affirmation of our approach so that we have a mutual understanding of our new testing directions, and so that our customers are assured of your concurrence.

Sincerely.